MMX8S reporting false motor temp.

[fredw90]

Has anyone else had this issue with the MMX8S? Went to do a few passes tonight. Did about 3-4 passes on 5s as a shake down. Pulled the car checked motor temps, roughly 130is over the entire outside of can. Let it cool off for about 10 minutes before I threw in the 6s pack. Did 2 solid passes on 6s and pulled to check temps with the temp gun. Can was around 120, could easily keep my hands on it. Let it sit for a few minutes. Can temp on outside dropped all the way below 100 degrees. Put the car down and set up the camera to record the next pass. Slowly start creeping down the road and I get the dreaded - - *. So I walk down and grab the car like wtf. Put my hand on the can and its nearly ambient temp (70*f). I let it sit for a few minutes, power cycled it and did another pass and it did it again. This is a brand new sensor cable, I'm wondering if it has anything to do with how the cable is routed(Under the motor comfortably). Im going to unplug, clean and plug the sensor cable back in and give it another shot . I also have some logs.

This is not the first instance of this happening so before the runs I did tonight I pulled the can apart and made sure everything looked good and all was well. I think what throws me off the most is the motor was cool as a cucumber and it decided to thermal.

How many of you speed run with the sensor cable plugged in? Or do you just run and monitor external temps of the motor?

Typhon 6s
1520 1650kv
30p/40s
Temp cutoff set to 160
Sensor cable nearly brand new
Esc and motor have maybe 2 weeks of use on them if not less

Here you can see where motor temp just decides to do its own thing after a few quick passes.

 

[dure16]

The gradual increase in motor temp looks pretty normal if you’re not letting it cool down enough between runs.

Castle recommends 180F temp cut off.

I’d try a new direct connect sensor cable from Castle. Ditch the little adapter thing if you’re still using it.

 

[SirCrashALot]

I have 3 different Castle systems and i never even got the temp sensor to work on two of them.

 

[fredw90]

The gradual increase in motor temp looks pretty normal if you’re not letting it cool down enough between runs.

Castle recommends 180F temp cut off.

I’d try a new direct connect sensor cable from Castle. Ditch the little adapter thing if you’re still using it.

@dure16
What throws me off is where it goes from 120 to 20 back to 120 and 20 twice towards the right hand side of that log.

I didnt even bother with the adapter. I did go straight to the direct connect sensor. I pulled the cable out blew out the connections, rerouted the sensor cable.

One thing to note, a few days ago before I started doing runs I got the * * *, three short beeps when I powered it up once or twice. Which indicated that it lost connection to the sensor. This was when the cable was brand new and just installed. After that I didnt have any issues. Ill order another direct cable just for the heck of it.

 

[dure16]

@dure16
What throws me off is where it goes from 120 to 20 back to 120 and 20 twice towards the right hand side of that log.

I didnt even bother with the adapter. I did go straight to the direct connect sensor. I pulled the cable out blew out the connections, rerouted the sensor cable.

One thing to note, a few days ago before I started doing runs I got the * * *, three short beeps when I powered it up once or twice. Which indicated that it lost connection to the sensor. This was when the cable was brand new and just installed. After that I didnt have any issues. Ill order another direct cable just for the heck of it.

Yeah I agree about the weird temp drops.

You might have a bad sensor in the motor. I’d ask Castle about it since you just bought it.

I have 3 different Castle systems and i never even got the temp sensor to work on two of them.

Weird. I have like 15 Castle systems and have never had a problem with the temp sensors.

 

[LibertyMKiii]

I have seen it read motor temps when there is no motor temp sensor being used LOL

 

[fredw90]

I messaged castle last night. We will see what they say.

 

[fredw90]

Replaced the cable, issues still persist. About to give up on the sensor cable and monitor temps manually. I can deal with not having sensored, the only reason I wanted it was for motor temps.

just got out here to do some testing after the car has been sitting for about a day, plugged it in and immediately got the overtemp warning, unplugged and reseated, now getting the three short beeps for motor signal lost.

Suggestions anyone? Don’t think it’s the esc as I haven’t had any problems with that and it runs cool as a cucumber. Motor does as well for how it’s geared and how I’m running it. It’s just the inconsistency of the damn sensor cable.

 

[dure16]

Replaced the cable, issues still persist. About to give up on the sensor cable and monitor temps manually. I can deal with not having sensored, the only reason I wanted it was for motor temps.

just got out here to do some testing after the car has been sitting for about a day, plugged it in and immediately got the overtemp warning, unplugged and reseated, now getting the three short beeps for motor signal lost.

Suggestions anyone? Don’t think it’s the esc as I haven’t had any problems with that and it runs cool as a cucumber. Motor does as well for how it’s geared and how I’m running it. It’s just the inconsistency of the damn sensor cable.

I’d guess bad temp sensor in the motor. If you’re not worried about temps, then just disable the motor temp cutoff. That should fix the problem and allow you to still have smooth, sensored power delivery.

What did Castle say about it?

 

[fredw90]

I told them I was replacing the cable before they had the chance to suggest it, they said that the ESC is an ESC first and a datalogger second. I messaged them again today will see what they say when the reply. Looking back at my post earlier, @dure16 I think youre right it might not even be the cable, could just be a faulty sensor in the can. (motor has only been parking lot bashed never jumped). Wonder if they sell just the sensor.

Its not really the sensored part that Im pressed on, because the system is pretty damn good starting off even when unsensored. I just wanted the temp protection .

Its odd, I still love the performance of the castle stuff. Based on motor rpm on this last log I pulled I hit around 96-97 earlier today. GPS will be here tomorrow.

This is making me itch to build the infraction I have sitting on my shelf. Maybe Ill order the mmx8s and 1717 1650 combo on amazon.

 

[dure16]

I told them I was replacing the cable before they had the chance to suggest it, they said that the ESC is an ESC first and a datalogger second. I messaged them again today will see what they say when the reply. Looking back at my post earlier, @dure16 I think youre right it might not even be the cable, could just be a faulty sensor in the can. (motor has only been parking lot bashed never jumped). Wonder if they sell just the sensor.

Its not really the sensored part that Im pressed on, because the system is pretty damn good starting off even when unsensored. I just wanted the temp protection .

Its odd, I still love the performance of the castle stuff. Based on motor rpm on this last log I pulled I hit around 96-97 earlier today. GPS will be here tomorrow.

This is making me itch to build the infraction I have sitting on my shelf. Maybe Ill order the mmx8s and 1717 1650 combo on amazon.

I’d keep pressing Castle. They’ll send you a new motor if they can’t figure out the problem.

 

[fredw90]

I’d keep pressing Castle. They’ll send you a new motor if they can’t figure out the problem.

I don't get it man, I put the old sensor cable back in and just did two packs back to back a 4s and a 5s with no issues whatsoever.

Only other change I made was turning off the "sensor loss warning".

Edit: I did also change the sampling rate to 2 per second instead of 5.

 

[SrC]

You tried all else, cables etc.
Sometimes if the Data logs are full and overwriting, you can get Erroneous data. Clear you data logs, and repeat Temp testing.
Ultimately, you may have a bad Sensor Board. This is where the Temp Thermistor sensor is. They can fail like anything else. It is not uncommon for sensor boards to fail. And always have a known good Spare sensor lead as a back up. When you own sensored setups, it's a must have.
Sometimes a Sensor Pin-Out is corroded. And not necessarily the Sensor lead being the issue.

>>>I would open the motor and clean it out well, lube the BB's while you are at it. Looking at the Sensor board closely. At the 3 Hall Effect sensors. Thermister is on that PCB. Observe for any arcing or burns. Spray out the Motors Sensor Pin-Outs as well. Only use CRC Electrical contact spray for all cleaning. Let evaporate well.
That's what I would try at this point.

 

[fredw90]

You tried all else, cables etc.
Sometimes if the Data logs are full and overwriting, you can get Erroneous data. Clear you data logs, and repeat Temp testing.
Ultimately, you may have a bad Sensor Board. This is where the Temp Thermistor sensor is. They can fail like anything else. It is not uncommon for sensor boards to fail. And always have a known good Spare sensor lead as a back up. When you own sensored setups, it's a must have.
Sometimes a Sensor Pin-Out is corroded. And not necessarily the Sensor lead being the issue.

>>>I would open the motor and clean it out well, lube the BB's while you are at it. Looking at the Sensor board closely. At the 3 Hall Effect sensors. Thermister is on that PCB. Observe for any arcing or burns. Spray out the Motors Sensor Pin-Outs as well. Only use CRC Electrical contact spray for all cleaning. Let evaporate well.
That's what I would try at this point.

Logs get cleared every time I pull them, which is usually every other battery pack or so, if not sooner.

Motor was pulled and disassembled, and cleaned earlier this week. But I did not look at it under a magnifying glass to see if I noticed anything abnormal.

Back to the older sensor cable worked just fine today. Will test again soon. Going to return the newest one. I did notice when installing the newest cable that the connection as the esc felt loose but was hoping that wouldn’t be an issue. I think it was unfortunately.